Artificial leg



J. R. B. NORFOLK.

ARTIFICIAL LEG.

APPLICATION FILED JUNE 9. I919.

1,852,682., Patented p 1920.

2 SHEETS- T l- J. R. B.- NORFOLK.

ARTIFICIAL LEG. APPLICATION FILED JUNE 9. 1919.

Patented Sept. 14, 1920.

2 SHEETS--SHEET-2- urur stares ATENT orr cs.

JOSEPH a. B. NoaroLK, or OHIOAQ LINOIS.

ARTIFICIAL LEG.

Application filed June 9, 1919. Serial No. 302,658.

1 To all whom 2'2) mag concern:

Be it known that I, JOSEPH R. B. NonroLu, a citizen ofthe United States,'residing at Chicago, in the county of Cook and State 1 of Illinois, have invented certain new and usc'l'ul Improvements in Artificial Legs, of

which the following is a specification. I

Myinven'tion relates to artificial legs, and has more particular reference to kneeoints O and suspender constructions therefor.

natural way, or to rise naturally from a sitting posture, and to perform other natural movements by strains exerted 'on the arti ficial leg. It is a further object to provide an improved structure for holding the artificial leg in all operative positions by a substantially uniform downwardpull upon the wearers shoulder, thus avoiding the wen.

known unequal or drawing strains which cause the suspender to move upon the shoulder, sometimes forward and sometimes rearward, attended by notable discomfort. A further object is to provide a structure whereby the movements or" the lower leg may be controlled by a shoulder independently of the shoulder which supports the leg, thus creating an advantageous division of labor for the shoulders and giving the wearer greater freedom and capacity for action than where the same shoulder or shoulders perform both operations. It is also an object to provide an improved form of adjustable stop for limiting the forward movement of thelower legrelative to the upper leg. A. further ob ect..1sto provide an improved leg-supportand-control mechstantially all forms of artificial legs and various forms of leg braces now in use. still further object is to providemeans for adjusting the hinge pin for the upper and lower leg members with respect to its bearing sons to maintain a tight joint there.

Otherobjects and advantages will appear hereinafter.

Specification of Letters Patent.

In the accompanying drav'v'ings which form a part of this specification I have illustrated-these improvements in What I now consider their most advantageous form as applied to an artificial leg. In these drawings Figure 1 shows the several parts in assembled relation,"inanoutside View; Fig.

Patenteaseptia, 1920.

2 is an enlarged substantially medial foreand-aft, vertical section'through the knee joint portions of the leg; Fig. 3 is a substantially medial, vertical section through the same parts at right angles'to the view of Fig. 2; Fig. 4 isa side View with knee portions of the upper leg broken away to show interior parts in side view.

The upper leg lO is a hollow structure formed to receive the stump of the Wearers 7' thigh, and may be made according to any.

well-known construction, usually being of light-weight wood. It has a knee portion at 11 which is rounded there substantially on the arc of'a circle having its center at the hinge pi1i12.YThishinge pin 12 in itself is of well :known construction. lar and is'threaded interiorly at its ends to receive the cap screws 13. To provide a strong seat for the hinge pin 12 I insert the transverse piece'll made of hard wood. This piece 14 acts as a bearing for the pin 12 and the weight of the wearers body is normally transmitted to the pin through this bearing member.

It is tubu- The lower leg 15 is similarly made of I light weight material, such as wood, is also a hollowstructure, and is formed substantially to interfit at its top with the knee portion 11 of the upper leg member, but with sufiic'ient clearance to. prevent frictional contact, as shown in Fig. 2. r

The upper and lower'leg members are somedium of a unitary structure which is rigidly secured to the lower leg and upon the hinge pin12. This unitary member is preferably formedof severalparts, chiefly cured operatively together through the for purposes of assembling and disassemanism which may readily be applied to subbling the knee joint structure. These parts comprise first a pair of normally vertical metallic side members 16, secured respecti'vely as by. boltsor screws-17 at opposite middle upper side portions of the lower log,

this member 16 having an enlargement pro-.

vided with an opening at its upperend pin 12 is exteriorly threaded at 23.

the main support for the lower leg member. Next in order is the cross bar member 18, which is also apertured to fit upon the end of the hinge pin 12, and next I provide the yoke member 19 which is secured, preferably by machine screws 20, to the cross car 18 and by a similar screw 21 to the supporting bar 16. After these screws 20 and 21 are inserted and drawn tight they are preferably battered a little at their inner ends to prevent accidental retraction, and in this connection it is pointed out that the unitary structure consisting of the parts 16, 18 and 19 may be assembled before the supporting bar 16 is secured to the lower leg. '1 he cap screws 18 in the ends of the pin 12 serve to hold this unitary structure upon the pin 12.

it will be noted that one end of the hinge The supporting member 16 on that side is intcriorly threaded to screw upon this threaded portion23. By thus connecting the hinge pin to one of the supports 16 the assembling of the device is facilitated.

The of the yoke member 19 act as struts and ties, making rigid and strong the connection between the cross member 18 and supporting element 16 so that the lower leg member may be controlled through strains exerted upon this cross member 18.

For exertin such controllin strains the b D cross member 18 is extended forward on each side to provide a pulling lever 25, and

this lever 25 is preferably in the form of a one-piece yoke of flat steel, the arms of which are the cross bars 18. This yoke 25 has a normally horizontal slot at 26 adapted the pull strap 27 passes upward and is.

formed loop-shaped at 27, this loop 27 normally encompassing the shoulder of the wearer on the same side as .is the artificial leg. Thus in the device illustrated the loop 27 passes over the wearers, left shoulder and the artificial leg is on the left side of his bod. When the le is in its 0 erative J r p 1 position the loop 22' nts snugly upon tne wearers shoulder so that when the artificial le 1s flexed at the knee *o1nt a l1ft111 'll) 2: J a; l

movement of the left shoulder will pull upon the strap 27, communicating its power to the lever 25 and thence to the supports ing element 16, thus straightening the leg, as shown in Fig. 1. In these movements of alternately flexing and straightening the leg the hinge pin 12 turns'upon the bearing block 14, the hinge pin being rigid with the pull lever 25 and with the parts 16 and 19 connected therewith.

in the head 32. Two set screws projecting through the head 82 impinge upon the middle portion of the bearing blocl: 88 and maintain the bearing block tightly upon the hinge pin 12, this feature taking up wear and preventing the objectionableand annoying looseness and clicking sound due to loose parts in a device of this kind.

Extending from the head 82 of the stop member is the bar 37 which is directed first toward the rear of the leg and thence downward into the upper part of the lower leg,

its lower end having a notch 38 through which passes the adjusting screw shaft 89. A ll-shaped nut 10 encompasses the end of the rod 87, and this nut is threadedupon the shaft 89 andacts as a carrier for the end of the rod 37. They shaft 39 has a head 12 adapted to be turned by a screw driver, while a washer e3 heldin place by a screw 1 1- prevents, in connection with the head 42, any longitudinal movement of the shaft 39.

Pieces of "metal. 1-5 and 46 are insertedat these places inthe lower leg'for purposes of better wear. The stop bar'37 travels in a normally vertical slot 46 in the lower middle rear of the upper leg whenever relative movement of the lower leg occurs. lhis slot terminates at 47, at which place a cushion element, such a piece of leather, is inserted to engage the stop 87. It will now be seen that by turning the screw shaft 39 one way or the other the stop 87 will engage the leather or the like at 47 with the lower leg perfectly straight up and down with respect to the upper leg, or bent slightly forward or rearwaru, according to the preference of the user, it being pointed out that some users prefer to have the lme of direction of the wearer when standing upon the artificial leg slightly forward of the hinge pin, others preferring this line of direction to pass through the dead center, while others prefer a slight bend forward at the knee when the stop device becomes effective.

The entire artificial leg is maintained in operative position by a flexible strap or holding member 50, which is substantiallv U-shapedand passes from theartificial leg upward and over-the shoulder on the oppoin front of the artificial leg through the retaining'yoke and. passes into the in,- terior of the upper leg through an openingaccommodating the roller 52, while at the rear the strap passes through a similar opening and in engagement Y with the roller 53. V

Upon the hinge pin 12 I provide a cross bar device in the nature-of a walking.

beam, the same fitting upon the shaft12 for rocking movement thereon.

This device 55 is an equalizer of the swingletree type. Its endsare turned over to form an eye at 56 adapted to accommodate the link 57, a screw 58 at each end hold I ing the link in the, eye 56. The ends of the holding strap50are secured to the links 57 respectively, and when so secured and the device in operative position the length 1 of the hold ng strap 50 18 such that the same fits snugly upon the wearers shoulder and maintains the upper leg: 10 in its desired re-.

lation to the wearers stump. p

The function of the equalizer bar 55 is to take up slack. in the'hold-ing strap 50, either front or back as the case may be, and pay out slack in the strap 50 at its other end. Thus when the wearer seats himself he naturally bends his body over in front. This causes slack in the front. extension of the strap 50 and at the same time the curvature of the wearers back increases the distance from the shoulder to the artificial leg behind and without some equalizing means the wearer would experience a tight drawing of the strap 50 upon his shoulder and back and this would be sufiicient to cause a slippage of the strap 50 upon his shoulder and back, which would be both annoying and hurtful.

With this equalizer bar connected to the strap 50 asillust-rated the pull upon the rear extension of the strap 50 draws up ward the rear arm of the equalizer 55, while the other end is freely permitted to move downward because of the slack in the front extension of the strap 50. No movement of the strap 50 therefore occurs on the wearers shoulder, but the artificial leg is at all times held in its desired relation to the stump.

It is not new to provide in artificial legs an equalizer of the type described, as witness the U. S; Patent to Frees, No. 401,426, of April 16, 1889. My improvedequalizer construction is highly advantageous over the one there shown for various reasons,

among which I may mention that no additional pivot over the one for the knee joint is required, thus taking advantage of the presence of an unusually strong hinge pin .'while avoiding the additional weight and expense of an additional bearing pin for .the equalizer; also in having a unitary mechanism forsupporting the leg and for controlling the lower. lega mechanism which can be readily;installed not only in new but alsoin old leg structures; furthermore the equalizer in my present device is maintained against lateral movement by its being in the bifurcation of the head 32, well shown in Fig. 3, solthat the-desiredaction is always to be had. It is furtheradvaa tageous in thatan adjustment of the hinge pin 12 to overcome looseness, as hereinafter pointed out, makesat the same time the de sired adjustment for the leg holding means.

The further feature of improvement referred to next hereinabove is in the provision of adjusting means for maintainingthe hin e pin 12 in tight-fitting operative relaion to its bearing 23 to overcome wear. These means comprise the two-part or yokelike head member 60, its two parts 60 being bored transversely to fit loosely upon the hinge pin 12. The yoke 60 carries the ,central stud 61 which passesthrough thetransverse metallic support, 62, andv the nut 63 draws the yoke 60 upward. i Vhen Wear occursin-the bearing block 14 so that there is looseness and play in the joint a slight turning of the nut 63 restores the desired fit.

I claim: i i 1. The combination of an upper leg member, a lower leg member, a l1inge- )in pivotally connecting said members, an equalizing bar pivotally mounted intermediate its ends on said hinge-pin, and a flexible suspender having one of its ends connected ,to oneend of said equalizing bar. and its'other end connected to the other end of the equalizing bar,

the suspender having a length enabling it to pass over the wearers shoulder and hold the artificial legin place.

- 2. The combination of an upper le member, having a knee portion, a lower leg member, a hinge-pin 'pivota-lly connecting f said members, a yoke extending forward outside the leg intront at the knee and havsaid members, a yoke extending forward from the hinge means and passing around the knee n front, means for connecting said yoke rigidly to the lower leg member, and v a flexible pull member connected to the yoke in front and having a loop for the wearers shoulder.

i. The combination of an upper leg member having a knee portion, a lower leg member pivotally connected to the upper leg member, a pull lever extending forward from thepivotal connection'of said members, means for holding said pull lever in rigid relation to the lower leg member, and means under the control of the wearer forpulling upon said pull member.

5. The combination of an upper leg member having a knee portion, a lower leg member pivotally connected to the upper leg member, an equalizing bar pivotally mounted intermediate its ends near the knee por ion, a flexible support adaptedto pass substantially U-shaped over one of the wearers shoulders and having its twoends connected to respective ends of said equalizing bar, a leg-control lever rigidly secured to the letter leg and extending forward to a point normally in front of the hinge connection between the leg members, and a flexible pull member secured to said pull lever and having a loop for the other shoulder of the wearer.

6. The combination or an upper leg memextending from front to back in the lower said stop member whereby turning said shaft moves said stop member forward or backward on its pivotal connection, and stopmeans on the lower leg adapted to come into contact with said stop member when the lower leg is moved forward on its hinge connection.

7. The combination of an upper leg member, a lower leg member, a hingepin connecting the two members pivotally, the upper leg member having a bearing for the hinge-pin, and adjustable means for limiting the relative movement of the lower leg including: a bar mounted on the hinge-pin and extending into the lower leg member, a threaded member mounted to rotate in the lower leg member, said arm being mounted on said threaded member to move relatively when said threaded member is rotated, and a stop on the upper leg member eg member, said shaft being threaded into ada ated to contact said bar the arran ement being such that by rotating said threaded member the forward movement of the'lower leg is variously limited.

JOSEPH R. B. NORFOLK. 

